Field of the Invention
The present invention generally relates to a motor, and more specifically relates to a motor for an air-conditioning unit and an air-conditioning unit comprising a motor.
Description of the Related Art
Many applications use brushless direct current (BLDC) motors. A known motor construction is an internal stator with radially outwardly extending electrically commutated poles, and an external rotor with permanent magnet poles arranged circumferentially and facing outer ends of the stator poles. Such a motor configuration may be described as an inside-out BLDC motor.
Inside-out BLDC motors have been used in air-conditioning units. The motor is used to drive a fan or blower of the air-conditioning unit. The fan or blower typically has an axial length that is many times the axial length of the motor. One end of the fan is coupled to the motor and an opposite end is supported by a bearing arrangement.
Due to the length of the fan, alignment of the fan, the rotor and the stator on a common rotational axis may be difficult. A circumferential air gap must be maintained between the stator poles and the rotor poles.
Vibration generated in the motor preferably is substantially isolated from the fan and motor mounting supports for quiet operation of the fan and the related air-conditioning unit.
The fan or blower of a modern air-conditioning unit typically has a diameter of about 100 mm. The motor preferably is of a compact size commensurate with the diameter of the fan and the motor preferably has a compact axial length. To achieve a compact size and to improve manufacturability, the motor and the connection of the motor to the fan assembly, preferably comprises few components.
In this specification, where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.
It is an object of the present invention to provide an improved motor, or an improved motor for an air-conditioning unit, or an improved air-conditioning unit, or to at least provide the industry or public with a useful choice.